Final answer:
The increased literacy during the seventeenth and eighteenth centuries in Great Britain influenced the style and content of literature by expanding the audience and introducing themes pertinent to the middle class. This was part of a broader trend of the Enlightenment where more people gained access to printed materials through the rise of libraries and reading clubs. The correct option is D.
Step-by-step explanation:
The change in Great Britain that influenced the style and content of seventeenth- and eighteenth-century literature was increased literacy. This period, also known as the Enlightenment, saw a rise in literacy among the middle and upper classes. The expansion of the reading public began with the wealthy but eventually extended to the middle class. Despite the Enlightenment's ideals about the spread of knowledge, real participation was initially limited to those with enough leisure time and money to afford books. Eventually, the introduction of lending libraries and reading clubs helped increase literacy levels among a wider public, which in turn affected literature by broadening the audience and introducing new themes that reflected the interests and lives of this emerging readership.
Obstacles that made it difficult for those at the lower end of the socioeconomic ladder to actively participate in the print culture included low levels of literacy and a lack of leisure time rather than a lack of interest or an outright shortage of books. As literacy rates gradually increased, so too did participation in the cultural and intellectual exchange that characterized the Enlightenment.